Background: Colonoscopy in combination with endoscopic polypectomy has been shown to be an efficient measure for reducing colorectal cancer incidence. In Germany, a colorectal cancer screening program based on colonoscopy for individuals aged 55 and above was introduced in 2002. However, for largely unknown reasons, participation rates remain low. The purpose of this study was to identify factors influencing compliance with colorectal cancer screening. Methods: A structured survey of 239 individuals aged 55-79 years ;was performed. Statistical analysis included chi(2) test, t test, principal component analysis, and logistic regression. Results: 56% of previously screened, but only 26% of non-screened individuals had received a recommendation to undergo screening colonoscopy. 50% of the non-screened believed a screening colonoscopy should only be performed in case of complaints. Univariate analysis identified participation in any secondary prevention measures (p < 0.001), concerns about colonoscopy (p < 0.012), and knowledge about colorectal cancer (p < 0.001) as critical issues distinguishing between groups. Multivariate analysis revealed that secondary prevention (p < 0.001) and concerns about colonoscopy (p = 0.026) were independent predictors of compliance with screening recommendations. Conclusion: Our survey has identified critical factors deterring compliance with colorectal cancer screening recommendations. This will help to direct future campaigns in order to increase participation in colorectal cancer screening. Copyright (C) 2010 S. Karger AG, Basel